JP2751583B2 - Aromatic diamine having ethylene oxide chain and method for producing the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an aromatic diamine having an ethylene oxide chain, which is useful as a raw material for epoxy resin curing agents, polyamides, polyimides, bisimide compounds, and the like, and a method for producing the same.

[Conventional technology]

Aromatic diamines are widely used as raw materials such as polyamides, polyimides and bisimide compounds, and as curing agents for epoxy resins for copper-clad laminates and fiber reinforcement.

Further, thermosetting bisimide compounds have excellent mechanical properties, electrical properties, and heat resistance, and are therefore used as resins for fiber-reinforced composite materials, printed wiring boards, heat-resistant molding materials, and the like.

However, bisimide compounds using ordinary diamines such as diaminodiphenylmethane and diaminodiphenylether as raw materials have the disadvantages of having good heat resistance but poor moldability and poor flexibility and impact resistance.

Therefore, in order to obtain a resin having excellent heat resistance, flexibility and impact resistance with a bisimide compound, a method using an aromatic diamine having an ether bond in a main chain as a raw material is used. For example, a heat-resistant bisimide-based resin composition shown in JP-B-63-17081 and an etherimide-based compound shown in JP-B-63-37786 are converted to an aromatic diamine of the formula (III). 2 represented by], 2- bis (4-aminophenoxy phenyl) propane is used.

Moreover, in order to improve the adhesiveness and impact resistance of the cured epoxy resin, a similar diamine that can impart flexibility to the cured product is used. For example, a varnish for a flame-retardant epoxy resin copper-clad laminate shown in JP-A-58-8639 has a similar formula [IV] to the diamine as a curing agent that improves both heat resistance and adhesiveness. 2,2-bis [4- (4-aminophenoxy) -3,5-dibromophenyl] propane is used.

Further, as an aromatic diamine for an epoxy resin curing agent that greatly improves impact resistance without compromising heat resistance, an epoxy resin for a fiber-reinforced prepreg disclosed in JP-A-62-36422 is used. Uses an aromatic diamine having an ethylene oxide chain in addition to the ether bond represented by the formula [V] .

[Problems to be Solved by the Invention] The method of using a heat-resistant bisimide-based resin composition described in JP-B-63-17081 and an etherimide-based compound described in JP-B-63-37786 discloses an ether in the main chain. Since aromatic diamine having a bond is used as a raw material, an ether group is introduced to impart flexibility, but the flexibility is still insufficient, so that it is still a brittle material having no toughness alone. was there.

Further, the method using a varnish for a flame-retardant epoxy resin copper-clad laminate described in JP-A-58-8639 also uses a brominated aromatic ether diamine as a curing agent, so that the cured product is slightly flexible. However, there is a problem that satisfactory properties are not obtained in adhesiveness to a copper foil.

Further, in the method using an epoxy resin for fiber reinforced prepreg described in JP-A-62-36422, an aromatic diamine having excellent flexibility having an ethylene oxide chain in addition to an ether bond in a main chain is used as a curing agent. Therefore, it has flexibility and sufficient impact resistance, but there is a problem that heat resistance and chemical resistance are reduced because less aminophenyl groups are bonded by ester bonds.

The present invention, when used as a raw material of a bisimide or polyimide resin or used as a curing agent for an epoxy resin, does not impair heat resistance and has sufficient flexibility for a bisimide or polyimide resin or a cured epoxy resin. The present invention provides a novel aromatic diamine having an ethylene oxide chain, which is excellent in flexibility, which can impart the compound, and an advantageous production method thereof.

[Means for solving the problem]

That is, the present invention relates to the general formula [I] (Wherein, X ^{1 to} X ⁴ represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and may be the same or different from each other.
R ¹ and R ² represent a hydrogen atom, a methyl group, an ethyl group, a trifluoromethyl group or a trichloromethyl group, and may be the same or different. n shows the integer of 1-3. The present invention provides an aromatic diamine having an ethylene oxide chain represented by the following formula:

Further, the present invention has the general formula (II) (Wherein X ^{1 to} X ⁴ , R ¹ , R ² and n are the same as described above) and nitrochlorobenzene or nitrofluorobenzene in an aprotic polar solvent using a basic catalyst. Reacting the aromatic diol to form a bis (nitrophenyl ether) compound of the aromatic diol, and then reducing the nitro group to an amino group.
An object of the present invention is to provide a method for producing an aromatic diamine having an ethylene oxide chain represented by the general formula [I].

By converting an aromatic diol having an ethylene oxide chain represented by the general formula (II) into an alcoholate using a suitable basic catalyst, it easily reacts with a nitrohalogenated benzene compound to form a corresponding nitrophenyl ether compound. By reducing this, an aromatic diamine having a novel ethylene oxide chain which can impart flexibility can be obtained.

The aromatic diamine having an ethylene oxide chain of the present invention has the effect of imparting flexibility with an increase in the value of n in the general formula [I]. However, when it is 4 or more, heat resistance is impaired, which is not preferable. .

The aprotic polar solvent in the production method of the present invention,
Although the type is not particularly limited, it is necessary to stabilize the formed alcoholate anion, and generally, N, N-dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide, N-methylpyrrolidone, hexamethylphosphoryltriamide and Tetrahydrofuran or the like is used.

As the basic catalyst, at least one selected from the group consisting of alkali metal carbonates, alkali metal hydroxides and active copper, and alkali metal hydrides is used. Generally, potassium carbonate, potassium hydroxide and activated copper, or sodium hydride is used. Stronger basic catalysts have higher yields of phenyl etherified compounds, and sodium hydride is the most preferred of the group.

As the amount of the basic catalyst, an amount necessary for converting the corresponding hydroxyl group into an alcoholate is used. That is, at least
0.5 molar equivalent, preferably 1.0 molar equivalent or more molar equivalent of basic catalyst is used.

The reduction of the bis (nitrophenyl ether) compound can be easily performed by a usual general method. For example, a reaction with a metal such as Sn, Fe, Zn or its chloride and hydrogen generated by an acidic substance such as hydrochloric acid or acetic acid, or a catalytic reduction using a metal such as platinum, palladium, nickel, cobalt or a Raney nickel catalyst as a catalyst The nitro group can be reduced to an amino group by the method.

By using the aromatic diamine having an ethylene oxide chain imparting flexibility of the present invention as a raw material, a flexible bisimide compound excellent in both heat resistance and impact resistance can be produced.

The above-mentioned flexible bisimide compound can be produced by a usual method of reacting a diamine with an acid anhydride or an acid halide. That is, a suitable solvent dehydrated aromatic diamine having an ethylene oxide chain imparting flexibility, for example, acetone, tetrahydrofuran, N,
An amic acid is produced by dissolving in N-dimethylformamide, N-methylpyrrolidone, or the like, and adding the acid anhydride or acid halide as it is or at room temperature or at room temperature or adding a solution. At this time, diamines may be added later to the acid anhydride or acid halide.

The generated amic acid is separated by filtration when it precipitates, and then proceeds to the next ring closing step. When the amic acid is obtained in the form of a solution, it can be directly proceeded to the next step.

Ring closure can be performed by so-called chemical ring closure. An acid anhydride such as acetic anhydride is usually used as a ring closing aid. As a catalyst for the ring closure reaction, inorganic salts such as nickel acetate, anhydrous potassium acetate, and cobalt acetate, and organic amines such as pyridine and triethylamine are used.

In addition, when the aromatic diamine having excellent flexibility of the present invention is used for a raw material such as a bisimide compound, polyimide, or polyamide, the type of the carboxylic acid component is not limited at all, and other conventionally known aromatic diamines may be used. There is no problem if used together.

Also, when the aromatic diamine having an ethylene oxide chain imparting flexibility of the present invention is used as an epoxy resin curing agent, the type of epoxy resin is not limited at all, and other conventionally known aromatic diamines and A curing agent such as dicyandiamide or a curing accelerator such as a tertiary amine or imidazole may be used in combination.

〔Example〕

Hereinafter, the present invention will be described in detail based on examples,
The present invention is not limited to this.

Example 1 An example of a method for producing an aromatic diamine having an ethylene oxide chain imparting novel flexibility provided by the present invention is described below.

126 g of DK Flex BPE-2P (ethylene oxide adduct of bisphenol A, trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was placed in a 21-necked flask equipped with a stirrer, a water content receiver, a condenser, and a thermometer. -Methylpyrrolidone 11 was added and dissolved. Then, while stirring, the content is about
35 g of 60% sodium hydride was added little by little and stirred for 30 minutes.

Next, 250 ml of toluene and 151 g of p-nitrochlorobenzene
Was added and completely dissolved, and then heated in an oil bath. The reaction was carried out at reflux temperature for 2 hours to distill water out of the system, and then toluene was distilled off, followed by a reaction at 175 to 180 ° C for 1 hour.

After cooling, the precipitated sodium chloride was separated by filtration, transferred to a pear-shaped flask, and N-methylpyrrolidone was distilled off under reduced pressure (58 ° C / 4 mmHg). Next, the obtained resinous material was washed with methanol to obtain 80 g of a precipitate.

In the infrared absorption spectrum of this precipitate, the absorption of the hydroxyl group around 3500 cm ^-1 disappeared, and the absorption of the nitro group appeared at 1340 cm ^-1 .

Next, the nitro group was reduced. 80 g of the above bis (p-nitrophenyl ether) compound was put into a three-necked three-necked flask equipped with a stirrer, a condenser, and a thermometer, and dissolved in benzene 31. While stirring on a hot water bath, activated iron prepared in advance with 1 kg of iron powder and 250 ml of concentrated hydrochloric acid was added little by little over 3 hours, and then reacted at 70 to 75 ° C. for 2 hours. Next, 250 ml of water was added and the reaction was further performed for 1 hour.

After cooling, insolubles were separated by filtration, and the benzene solution was transferred to a separating funnel and washed twice with water. Next, after adding anhydrous sodium sulfate and drying all day and night, benzene is volatilized to obtain 54 g of a solid substance.
I got In the infrared absorption spectrum of this powder, 1340 cm ^-1
The absorption of the nearby nitro group disappears and a new 3350-3500 cm ^-1
Showed two absorptions of primary amine.

Absorption of CH ₃ isopropenyl group 2900～3000Cm ^-1 In addition to the above primary amine absorption, absorption of the aromatic ether 1240 cm ^-1, absorption of ethylene oxide chain was observed at 1000~1100cm ^-1.

From the above, the aromatic diamine compound obtained in Example 1 is a novel aromatic diamine of the present invention represented by the formula [I] Is confirmed to be a bis (p-aminophenyl ether) compound of a bisphenol A ethylene oxide adduct having

Example 2 Next, a method for producing a bisimide compound using the above aromatic diamine as a raw material and characteristics of a cured product thereof will be described.

500m with stirrer, condenser and gas inlet tube
1 g of a three-necked flask was charged with 50 g of the aromatic diamine of the present invention prepared in Example 1, and dissolved in 200 ml of acetone. 50 ml of an acetone solution in which 22 g of maleic anhydride was dissolved was added dropwise over 1 hour under a nitrogen stream on an ice bath. After dropping, at room temperature
Stirred for hours. The precipitated amic acid was filtered, washed with acetone to remove excess maleic anhydride, and dried under reduced pressure.

Next, a stirrer, condenser and gas inlet tube were provided.
52 g of the above amic acid was charged into a 500 ml three-necked flask,
-Dissolved in 200 ml of methylpyrrolidone. Then, 14 ml of triethylamine and 1.25 g of nickel (II) acetate tetrahydrate
Was added and dissolved.

Then, 30 ml of acetic anhydride was added dropwise over 1 hour under a nitrogen stream at room temperature, and then the mixture was stirred and reacted at room temperature for 24 hours.

After cooling, the reaction mixture was reprecipitated in water, filtered, neutralized with an aqueous sodium hydrogen carbonate solution, and then sufficiently washed with water. After drying under reduced pressure, 46 g of the flexible bismaleimide compound of the present invention was obtained.

Next, a cured product of this bismaleimidated product was prepared and its mechanical properties were measured. 35 g of the maleimide compound and 2-ethyl-
0.5 g of 4-methylimidazole was put into a 2 mm thick Teflon spacer sandwiched between stainless steel head plates. Next, it was cured at 170 ° C. for 30 minutes at a contact pressure and then at 170 ° C. for 2 hours at 10 kg / cm ² to obtain a cured product of 100 mm × 2 mm. Then in the oven for 20
After-curing was performed at 0 ° C. for 1 hour and finally at 280 ° C. for 1 hour.

Cut out a test piece of 5 mm width and 50 mm length from this cured product,
A bending test was performed at a distance between fulcrums of 30 mm.

Comparative Example 1 In Example 2, a bismaleimidated product and a cured product thereof were produced in the same manner as in Example 2 except that 4,4'-diaminodiphenylmethane was used as the diamine component instead of the aromatic diamine of the present invention. Then, a bending test was performed.

Comparative Example 2 As in Comparative Example 1, 2,2-bis [4
Using (-(4-aminophenoxy) phenyl] propane, a bismaleimidated product and a cured product thereof were prepared and subjected to a bending test.

Table 1 shows the bending strength test results of Example 2 and Comparative Examples 1 and 2.

From Table 1, it can be seen that the aromatic diamine of the present invention has an ethylene oxide chain in the molecule, and therefore, when used as a raw material of a bismaleimide-based compound, is advantageous in making the cured product flexible and tough. it is obvious.

[Effects of the Invention] The present invention provides a novel aromatic diamine having an ethylene oxide chain which imparts flexibility as compared with the related art, and a process for producing the same. Compounds can now be obtained.

Claims (6)

(57) [Claims] 1. A compound of the formula [I] (Wherein, X ^{1 to} X ⁴ represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and may be the same or different from each other.
R ¹ and R ² represent a hydrogen atom, a methyl group, an ethyl group, a trifluoromethyl group or a trichloromethyl group, and may be the same or different. n shows the integer of 1-3. An aromatic diamine having an ethylene oxide chain represented by the formula: 2. The aromatic diamine having an ethylene oxide chain according to claim 1, wherein the compound represented by the general formula [I] is 2,2-bis [4- (β-p-aminophenoxyethoxy) phenyl] propane. . 3. A compound of the general formula [II] (Wherein X ^{1 to} X ⁴ represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and may be the same or different from each other. R ¹
And R ² represent a hydrogen atom, a methyl group, an ethyl group, a trifluoromethyl group or a trichloromethyl group, which may be the same or different. n shows the integer of 1-3. ) Is reacted with nitrochlorobenzene or nitrofluorobenzene in an aprotic polar solvent using a basic catalyst to synthesize a bis (nitrophenyl ether) compound of the aromatic diol. Wherein the nitro group is then reduced to an amino group, (Wherein, X ^{1 to} X ⁴ , R ¹ and R ² , and n are the same as those described above). 4. The method for producing an aromatic diamine having an ethylene oxide chain according to claim 3, wherein the compound represented by the general formula [II] is 2,2-bis (4-hydroxyethoxyphenyl) propane. 5. The ethylene oxide chain according to claim 3, wherein the basic catalyst is at least one selected from the group consisting of alkali metal carbonates, alkali metal hydroxides and active copper, and alkali metal hydrides. A method for producing an aromatic diamine having 6. The process for producing an aromatic diamine having an ethylene oxide chain according to claim 3, wherein the basic catalyst is at least one selected from the group consisting of potassium carbonate, potassium hydroxide and active copper, and sodium hydride. Method.